In recent years, mobile wireless communications have become increasingly popular. Initial implementations of mobile wireless communications, for example in the form of cellular telephone networks, supported circuit switched voice communication services. The carriers developed short message service (SMS) technology to provide text and/or e-mail communications via the wireless communication networks. As the wireless communication networks have evolved to provide greater bandwidth and packet based services, the industry has developed a variety of data services, such as email, web browsing, as well as a variety of services using multimedia message service (MMS) technology. Further, mobile devices have evolved to include an ever increasing number of features, including WiFi internet access and global positioning system (GPS) capability. While the features and capabilities of mobile devices are steadily increasing, the dimensions of mobile devices are decreasing in size.
To accommodate the increasing demand in wireless services, wireless packet data communication is being provided with ever increasing transmission speed. The packet data communication allows mobile device users to expand the scope of their use of the mobile device, for example, to enjoy multimedia services at a speed comparable to those enjoyed via Internet connected personal computers (PCs). The shift from third generation (3G) to fourth generation (4G) telecommunication data services marks another significant step in providing improved data service. For example, download speeds in 4G can be about ten times faster than 3G, sometimes reaching residential broadband service speed. Further, the frequency spectrum used in 4G can better penetrate buildings, offering better signal strength. Until a complete transition to 4G occurs, many 4G mobile devices provide backward compatibility to 3G.
Mobile devices often use multiple antennae at the transmitter and receiver to facilitate communication and backward compatibility. For example, with the advent of long term evolution (LTE) technology, at least two antennae are required: one for receiving and one for transmission. Further, different antennae are used for 4G and 3G (for downward compatibility). Further, there may be additional antennae for GPS, Global System for Mobile Communication (GSM), and Bluetooth, WiFi, etc.
Including such a large number of antennae in an ever shrinking form factor is a challenge. For example, a transmit antenna may experience crosstalk due to mutual coupling between the antennae when a signal transmitted by one antenna couples to, and is therefore received by, one or more of the other transmit antennae. Such crosstalk effectively couples the transmitters, which may cause various transmitter problems, e.g., back intermodulation interference at the transmitter output terminals, transmitter mismatch, efficiency loss, etc. Mobile devices may reduce and/or eliminate the mutual coupling by physically separating the antennae to spatially isolate the antennae. In this regard, some antennae are placed on back covers to provide sufficient separation between antennae.
In order to provide sufficient signal strength, the contact of an antenna between the back cover and the main unit must be secure. For example, a secure connection is provided when the back cover is properly connected to the main unit and the contacts between the back cover and the main unit align such that there is electrical contact. In many situations, however, the back cover is not secured properly. For example, a mobile device could be dropped, or the back cover may not be secured properly after a component (e.g., battery or chip) is replaced in the phone, etc. When the back cover of a mobile device is not properly secured, an antenna may not have proper contact with its coupling device on the other side of the mobile device. Thus, when a connection between the antenna and its respective receiving device is poor, the performance related to the antenna degrades. For example, the GPS may not be able to communicate with satellites, the 3G/4G may not be able to communicate with its respective base station (BS), or a WiFi signal may substantially degrade.
The user of a mobile device may not be aware that a loss of functionality is due to a poor antenna contact. Instead, a user may conclude that the mobile device is defective and ultimately return the mobile device. There currently is no effective means of providing a notification that an antenna is not properly secured to the mobile device.